This application claims benefit of Japanese Applications No. Hei 11-287124 filed in Japan on Oct. 7, 1999, No. 2000-3950 filed in Japan on Jan. 12, 2000, and No. 2000-257724 filed in Japan on Aug. 28, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to a camera having a photographic lens whose focal length can be changed or varied and which can be driven at a storable position, a photographable position, a photographic preparation, or the like,
2. Description of the Related Art
A conventional camera having a zoom lens barrel whose focal length can be changed and which can be moved between a storable position and a photographable position in a collapsible-barrel type camera is disclosed in Japanese Unexamined Patent Publication No. 11-24118. In this camera, a barrel is automatically moved into a collapsed position when a photographic operation of the camera is not performed for a predetermined time period, i.e., when a non-operation state continues for a predetermined time period in a photographable state. When the barrel is stored, the barrel is protected from unexpected external force.
However, in the collapsible-barrel type camera disclosed in Japanese Unexamined Patent Publication No. 11-24118, the lens barrel is collapsed after a predetermined time period irrespective of the operating position of the lens barrel. This is undesirable.
When the lens barrel is in the zoom position, it extends a long distance out of the camera and can be easily damaged. As such, it is desirable to withdraw the lens barrel into the collapsed position after a relatively short period of time has passed without the camera being operated. In contrast, the lens barrel only extends a short distance from the camera when it is in the wide angle position. Since it is less likely to be damaged in this position, it is safe to wait a longer period of time before moving the lens barrel into the collapsed position.
Because Japanese Unexamined Patent Publication No. 11-24118 waits the same period of time before withdrawing the lens barrel into the collapsed position irrespective of the operating position (zoom or wide angle) of the lens barrel, it will withdraw the lens barrel into the collapsed, non-operative, position sooner than necessary when it is in the wide angle position. This is undesirable for several reasons.
A user may miss the moment for a good picture because a long time period is required to re-extend the lens barrel and perform a photographic preparation again. In addition, the lens barrel is unnecessarily reciprocated and power consumption increases.
The present invention is made to solve the above drawbacks, and has as its object to provide a camera in which a photographic lens whose focal length can be changed or varied can be driven to a storage position and a photographable position, wherein the photographic lens is automatically withdrawn to an appropriate timing, a lens frame is sufficiently protected, and the photographic lens is not unnecessarily collapsed to avoid from missing the moment for a good picture.
According to the present invention, there is provided to a camera including: a photographic lens having an optical system whose focal length can be changed or varied; a photographic lens drive mechanism for driving the photographic lens to a position of a storage state and a position of a photographable state and for driving the photographic lens to change or vary the focal length of the photographic lens; an encoder for detecting the focal length of the photographic lens; a timer for clocking a non-operation state continuation time of the camera in the photographable state; a timer output decision circuit, having pieces of reference decision time information to be compared with a clocking output from the timer, for comparing the clocking output with one of the pieces of reference decision time information according to an output from the encoder to decide whether the output from the timer reaches the reference decision time information or not; and a control circuit for driving the photographic lens drive mechanism according to an output from the timer output decision circuit to drive the photographic lens to the position of the storage state, wherein the photographic lens is driven to be automatically withdrawn to the position of the storage state at a necessary timing on the basis of an output from the encoder and an output from the timer to effectively protect a lens frame.
Other characteristic features and advantages of the present invention will be apparent from the following description.